In parenteral packaging of medicine that is taken into the body or administered in a manner other than through the digestive tract, as by intravenous or intramuscular injection, glass is the most common material used for storage of drug products. Glass, especially type I borosilicate glass, is desirable for its strength, resistance to temperature variation, and general biological and chemical compatibility. With the advent of superior visual inspection methods there has been an increase in reports of small particles found within drug vials.
One example of great concern within the pharmaceutical community is the issue of glass delamination. Glass delamination is the sudden appearance of glass flakes or lamellae found within drug packaging that appear to have originated from the vial itself. In these cases the drug product reacts with the glass and causes some breakage into the drug solution.
Some tools have been developed to allow for the detection of glass flakes within a vial, but to date well-defined metrological tools are still lacking. Currently the community tends to utilize glass microspheres available from the National Institute of Standards and Technology (NIST, Gaithersburg, Md.), to simulate glass flakes, but these can be inadequate as they lack the morphology, and unique optical characteristics of a flake. Current particle standards are available with either a known size or defined number/concentration of particles, but not both parameters.
The present invention pertains to at least a process to create standard structures or samples with similar chemical, morphological and dimensional characteristics of actual glass flakes as seen in drug products. The aim is to advance the art and utilize these standards with detection and drug characterization equipment to determine the capability of detecting glass flakes.